Possibly the Greatest Alchemist of All Time, Vol 6

Takumi, a young, former Japanese man, is enjoying his life in another world by making full use of his strongest skill, alchemy. His skills as a crafter have been recognized, and he finally gets granted a meeting with the king. The carriage he built as a means of transportation to the royal capital is decked out with dreamlike features, and his friends are excited (and they run wild)! When Papek, the merchant, sees the carriage, he makes Takumi a certain proposal... In addition to all this, Takumi decides to look for an assistant in the royal capital in order to increase his production capacity! At the slave trading company he visits, he meets Reyva, a beautiful girl with animal ears who is interested in alchemy. Reyva looks to be serious, but she also seems to have an unusual side to her...